Are you making the arms the same length as the current ones? If so, its simple, just unbolt the old ones and slide in the new ones. Do them one at a time.
If you're changing the length of the arms then I'd do them in sets. Either do the uppers or lowers first. Use a combo of a floor jack, jackstands, ratchet strap, and various jacking points to pivot the axle to make the bolt holes line up with the holes in the arms. Installing the arms can be a PITA if you're trying to wrestle the axle around by yourself without the correct tools.
Make sure you don't fully torque the bolts down until you have the weight of the jeep sitting on the suspension, or you'll be replacing the bushing real soon!
